A wireless based position system uses wireless LAN (WLAN), wireless fidelity (Wi-Fi), a wireless broadband internet, world interoperability for microwave access, a high speed downlink packet access (HSDPA), Zigbee, Bluetooth, ultra-wideband (UWB), infrared data association (IrDA), ultra wild band, shared wireless access protocol (SWAP), long term evolution (LTE), and the like, which have been widely used, and therefore is considerably effective in costs.
A wireless network which is a part of communication infrastructure may implement a position system using a notebook computer, a PDA, a smart phone, or other wireless mobile devices and a software based position solution is remarkably cheaper than a position tracking structure which is used only in the interior of room.
Wireless based positioning technologies according to the related art generally use various methods to relatively triangulate a position. A standard for wireless position solutions is not yet present, each solution is specialized for a vendor and thus uses an independent Patent technology, and detailed matters for determining a position of a user are not yet published.
A general technology for indoor position estimation according to the related art may be classified into a cell ID method which recognizes cell identification of an access point, a multilateral positioning method using a received signal strength indicator (RSSI) which calculates a position based on a difference in signal strength between base stations, a radio frequency (RF) fingerprint method using radio wave strengths for each position, and the like.
The cell ID method may have a large error, the multilateral positioning method using an RSSI may have a reduced throughput due to interference between signals at several access points and an increased infrastructure cost burden, and the RF fingerprint method may have large calculations and may be sensitive to a change in environment.
Korean Patent No. 10-0775858 (Application No.: 10-2006-109443, filing date: Nov. 7, 2006) discloses a system and a method for environment analysis for indoor wireless location.
However, the above-mentioned methods may not perform the efficient positioning compared to costs.